Integrated circuits are typically manufactured from electronic circuits which are first formed on a semiconductor wafer. After the circuits are formed, the wafer is then diced into individual circuit-containing chips which, when packaged, form an integrated circuit. It is desirable during the manufacturing process to keep the chips arrayed to facilitate their testing. For this reason, once the circuits have been formed on the wafer, the wafer is set on an adhesive diaphragm. The wafer is then diced on the diaphragm such that the diaphragm remains intact, keeping the chips arrayed.
Separation of the chips from the diaphragm has been accomplished in the past by placing the diaphragm on a x-y table having a central opening seated within which is a die ejector. The x-y table displaces the diaphragm so that a selected chip overlies the die ejector. Actuating the die ejector pin serves to separate the chip from the diaphragm. A vacuum pickup tool, typically carried by a robot, is then positioned over the just-separated chip to engage it so the chip can be transported to a desired location. An example of a apparatus for accomplishing chip separation and pickup in the manner just described is found in U.S. Pat. No. 4,556,362, issued on Dec. 3, 1985, to N. Bahnck et al. and assigned to AT&T Technologies.
Chip separation and chip pickup, as presently practiced, require two separate positioning operations. First the diaphragm must be positioned over the die ejector and then the pickup device must be positioned over the separated chip. Each positioning must be carried out precisely, thus necessitating an accurate positioning system (e.g., a servo motor and associated electronics) which is usually expensive.
Thus there is need for a technique which reduces the number of positioning operations required to accomplish chip separation and chip pickup.